Open-Label Extension Study of DCCR in PWS Followed by Double-Blind, Placebo-Controlled, Randomized Withdrawal Period

Phase 3

Completed

• Conditions: Prader-Willi Syndrome
• Interventions: Drug: DCCR; Drug: Placebo for DCCR

• Registration Number: NCT03714373
• Lead Sponsor: Soleno Therapeutics, Inc.

Brief Summary

This is a multi-center, multi-period study with an open-label period followed by a double-blind, placebo-controlled, randomized withdrawal period evaluating the safety and efficacy of DCCR treatment.

Detailed Description

115 PWS participants who completed clinical study C601 will be enrolled into the OLE Period. All participants in the Open Label Extension (OLE) Period will receive open-label DCCR. The actual number of participants eligible to enroll in the double-blind, placebo-controlled, randomized withdrawal (RW) period will be limited to those participants taking DCCR in the OLE Period at the time of the RW Period Visit 1 (Baseline/Randomization Visit).The treatment groups in the C602 RW Period are those participants randomized to receive DCCR and those participants randomized to receive Placebo. Participants will be randomized in a 1:1 ratio (DCCR:Placebo).

Study Timeline

• Study First Submitted: 2018-09-27
• Study Start: 2018-10-01
• Study First Submitted QC: 2018-10-19
• Study First Posted: 2018-10-22
• Primary Completion: 2023-08-17
• Study Completion: 2023-08-17
• Status Verified: 2024-04
• Last Update Submitted: 2024-04-18
• Last Update Posted: 2024-04-19

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 115

Inclusion Criteria

• Successful completion of clinical study C601
• Provide voluntary, written informed consent (parent(s) / legal guardian(s) of patient); provide voluntary, written assent (subjects, as appropriate)

OLE Period Key

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Exclusion Criteria

• Positive urine pregnancy test (in females of child-bearing potential) or females who are pregnant or breastfeeding, and/or plan to become pregnant or to breast-feed during or within 90 days after study participation
• Any new disease, condition, or circumstance which would prevent, in the opinion of the Investigator, the patient from completing all study visits and assessments required by the protocol (e.g., an anticipated change of care setting)

RW Period Key Inclusion Criteria:

• Provide voluntary, written informed consent (parent[s] / legal guardian[s] of participant); provide voluntary, written assent (participants, as appropriate); this includes consent for randomization and potential treatment with placebo for up to 16 weeks
• Currently participating in clinical study C602 and complete the OLE End of Treatment Visit procedures

RW Period Key Exclusion Criteria:

• Positive urine pregnancy test (in females of child-bearing potential)
• Females who are pregnant or breastfeeding, and/or plan to become pregnant or to breast-feed during or within 30 days after study participation

Read More

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
RW DCCR	DCCR	75 - 525 mg DCCR
RW Placebo	Placebo for DCCR	75 - 525 mg Placebo for DCCR
OLE DCCR	DCCR	75 - 525 mg DCCR

Primary Outcome Measures

Name	Time	Method
Assess the safety of DCCR by evaluating the incidence and severity of adverse events reported	Baseline to end of OLE (up to 4 years)	Safety analyses will be conducted in all participants who receive at least one dose of DCCR. Adverse events will be described by type and level of severity.
Change from RW Period Baseline in HQ-CT Total Score	RW Period Baseline to Week 16	Hyperphagia-related behaviors will be assessed by the hyperphagia questionnaire for clinical trials (HQ-CT), an instrument designed to measure symptoms of food related preoccupations and behaviors. The HQ-CT consists of nine items with responses ranging from 0-4 (best to worst). Scores from 9 items will be summed for a possible total score range of 0-36.

Secondary Outcome Measures

Name	Time	Method
Change in Body Fat Mass	Baseline to end of OLE (up to 4 years)	Change in Body Fat Mass (kg) using DXA
Clinical Global Impression of Improvement (CGI-I)	RW Period Week 16	CGI-I is a single statement designed to assess the Investigator's overall perception of change in the subject's condition across the course of the clinical trial. The Investigator provides a response to "Compared to the subject's condition at enrollment, the subject's condition is:" by rating the subject's behavior using a 7-point response scale (best to worst).
Clinical Global Impression of Severity (CGI-S)	RW Period Week 16	The CGI-S is a single statement designed to assess the Investigator's overall perception of the severity of the participant's illness across the course of the clinical trial. The Investigator provides a response to "Considering your total clinical experience with this particular population, how ill is this participant at this time:" by rating the subject's behavior using a 7-point response scale (best to worst).
Assess the safety of DCCR by evaluating the incidence and severity of adverse events reported	through the end of the RW Period, 16 weeks	Safety analyses will be conducted in all participants who receive at least one dose of randomized withdrawal study drug. Adverse events will be described by type and level of severity.
Change from Baseline in HQ-CT Total Score	Baseline to end of OLE (up to 4 years)	Hyperphagia-related behaviors will be assessed by the hyperphagia questionnaire for clinical trials (HQ-CT), an instrument designed to measure symptoms of food related preoccupations and behaviors. The HQ-CT consists of nine items with responses ranging from 0-4 (best to worst). Scores from 9 items will be summed for a possible total score range of 0-36.

Trial Locations

Locations (28)

Research Institute of Dallas; 🇺🇸 Dallas, Texas, United States

Boston Children's Hospital; 🇺🇸 Boston, Massachusetts, United States

Seattle Children's Hospital; 🇺🇸 Seattle, Washington, United States

NYU Winthrop Hospital; 🇺🇸 Mineola, New York, United States

University of California, Irvine; 🇺🇸 Orange, California, United States

Stanford University; 🇺🇸 Palo Alto, California, United States

Chelsea and Westminster Hospital; 🇬🇧 London, United Kingdom

University Hospitals Cleveland Medical Center; 🇺🇸 Cleveland, Ohio, United States

The Research Institute at Nationwide Children's Hospital; 🇺🇸 Columbus, Ohio, United States

Hull and East Yorkshire Hospitals NHS Trust; 🇬🇧 Hull, Yorkshire, United Kingdom

Birmingham Women's and Children's Hospital; 🇬🇧 Birmingham, United Kingdom

Fulbourn Hospital; 🇬🇧 Cambridge, United Kingdom

Aintree University Hospital NHS Foundation Trust; 🇬🇧 Liverpool, United Kingdom

Royal London Hospital; 🇬🇧 London, United Kingdom

Kansas University Medical Center; 🇺🇸 Kansas City, Kansas, United States

Emory Children's Center; 🇺🇸 Atlanta, Georgia, United States

Sparrow Clinical Research Institute; 🇺🇸 Lansing, Michigan, United States

Children's Minnesota; 🇺🇸 Saint Paul, Minnesota, United States

St. Joseph's University Medical Center; 🇺🇸 Paterson, New Jersey, United States

The Queen Elizabeth University; 🇬🇧 Glasgow, Scottland, United Kingdom

Hammersmith Hospital; 🇬🇧 London, United Kingdom

Indiana University School of Medicine; 🇺🇸 Indianapolis, Indiana, United States

National Institutes of Health Hatfield Clinical Research Center; 🇺🇸 Bethesda, Maryland, United States

Rady Children's Hospital San Diego; 🇺🇸 San Diego, California, United States

Children's Hospital Colorado; 🇺🇸 Aurora, Colorado, United States

University of Florida Gainesville; 🇺🇸 Gainesville, Florida, United States

University of Utah; 🇺🇸 Salt Lake City, Utah, United States

Vanderbilt University; 🇺🇸 Nashville, Tennessee, United States